Amy Klobuchar has laid the grounds for a presidential run on an image of “Minnesota nice.”

But behind the doors of her Washington, DC, office, the Minnesota Democrat ran a workplace controlled by fear, anger, and shame, according to interviews with eight former staffers, one that many employees found intolerably cruel. She demeaned and berated her staff almost daily, subjecting them to bouts of explosive rage and regular humiliation within the office, according to interviews and dozens of emails reviewed by BuzzFeed News.

That anger regularly left employees in tears, four former staffers said. She yelled, threw papers, and sometimes even hurled objects; one aide was accidentally hit with a flying binder, according to someone who saw it happen, though the staffer said the senator did not intend to hit anyone with the binder when she threw it.

“I cried. I cried, like, all the time,” said one former staffer.

In the emails seen by BuzzFeed, often sent between 1 and 4 in the morning, Klobuchar regularly berated employees, often in all capital letters, over minor mistakes, misunderstandings, and misplaced commas. Klobuchar, in the emails, which were mostly sent over the past few years, referred to her staff’s work as “the worst in ... years,” and “the worst in my life.”

When staffers made mistakes, the emails show, she reamed them out — and sometimes, emails show, threatened to fire them — over threads that included many of their colleagues.